Ku frequency band linear polarization phased-array antenna and control method and channel calibration method thereof

Abstract

The invention discloses a Ku-band arbitrary linear polarization phased-array antenna and a control and calibration method thereof. The antenna comprises a printed board and a signal receiving chip, a plurality of dual-line polarized antenna units are arranged on the printed board, and every two adjacent units form an antenna subarray; the polarization directions of the two antenna units at the diagonal positions in the sub-array are rotationally symmetrical about the center of the sub-array, so that the phases of the cross polarization components are opposite and offset mutually. According to the control method, the channel phase difference is configured to be 0 degree or 180 degrees according to the quadrant to which the target polarization angle belongs, and the fine adjustment of the polarization angle in the quadrant is realized by using the amplitude attenuation difference between the channels. According to the invention, array plane geometric symmetry layout is combined with an amplitude-phase combined control strategy, and high linear polarization isolation and high-precision polarization control capability can be obtained without a complex polarization network.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a Ku-band linearly polarized phased array antenna and its control method and channel calibration method. Background Technology

[0002] In Ku-band satellite communication systems, circular polarization and linear polarization are commonly used. For linearly polarized satellite communication systems, the satellite signal is further divided into two orthogonal linearly polarized signals, horizontally polarized and vertically polarized, for frequency reuse. The condition for reuse is sufficient isolation between the two linearly polarized signals to prevent mutual interference. The metric for measuring this polarization isolation characteristic of antenna equipment is called polarization isolation. The quality of this metric directly affects communication performance; insufficient isolation will cause the two orthogonally polarized signals to interfere with each other, preventing normal communication.

[0003] With technological advancements and cost reductions, phased array technology is increasingly being applied in satellite communications. This technology controls the amplitude and phase of each radiating element in an antenna array, thereby altering the beam direction and polarization of the antenna array. Existing phased array technologies for achieving arbitrary linear polarization primarily employ the following methods, along with their advantages and disadvantages: Method 1: The phased array antenna elements are designed with half horizontally polarized antenna elements and half vertically polarized antenna elements. When receiving arbitrary linearly polarized waves, both types of antenna elements will always receive certain polarization components. The polarization characteristics of the receiving array can then be adjusted by amplifying, phase-shifting, and attenuating the signal through a polarization combining circuit, achieving arbitrary linear polarization matching. Each antenna element in this method corresponds to one receiving channel, resulting in relatively low power consumption. However, this method has the disadvantage of low aperture efficiency.

[0004] Method 2: The phased array antenna elements are designed as dual-polarization elements, meaning that one antenna element can simultaneously receive both horizontal and vertical polarization signals. When an arbitrary linear polarization signal is input, one antenna element can completely receive both the horizontal and vertical polarization components of that linear polarization signal. The two orthogonal polarization signals are amplified, phase-shifted, attenuated, and synthesized respectively to obtain the synthesized signal of arbitrary linear polarization.

[0005] Compared to Method 1, this method achieves higher array aperture efficiency, reaching the theoretical level. Chinese patent CN210744162U provides an embodiment using this method, enabling arbitrary switching between linear polarization, left-hand circular polarization, and right-hand circular polarization; however, the feed phase distribution it provides cannot achieve arbitrary linear polarization control. Furthermore, the array's polarization isolation depends solely on the antenna elements, making it difficult to improve the array's polarization isolation.

[0006] Method 3: The phased array antenna elements are designed as dual circular polarization elements, meaning that one antenna element can simultaneously receive both left-hand and right-hand circular polarization signals. When arbitrary linear polarization is input, one antenna element can completely receive both the left-hand and right-hand circular polarization components of that linear polarization signal. The two orthogonally polarized signals are amplified, phase-shifted, and synthesized respectively to obtain the synthesized signal of arbitrary linear polarization. Compared to Method 1, this method has higher array aperture efficiency, reaching the theoretical level. In existing technologies, the polarization angle of the phased array antenna is adjusted by adjusting the amplitude and phase difference between the left and right rotations, thereby achieving polarization tracking. Due to the wide bandwidth of Ku-band downlink receiving antennas, it is usually difficult to design the antenna directly as a circular polarization antenna. Instead, a bridge circuit is used to convert the linear polarization antenna into a circular polarization antenna, which is one of the disadvantages of this method, requiring the addition of a bridge circuit, making the circuit relatively complex. Another drawback of this method is that the polarization angle control step of linear polarization is related to the number of phase shifters. Under the condition of the most common 6 phase shifters in the Ku band, the polarization angle step is about 2.8°, which cannot achieve finer polarization angle control accuracy.

[0007] Method 4: In the existing technology, there is also a method of switching the linear polarization angle by combining a three-feed point-line polarization unit with a polarization switching switch. This method saves the amplitude and phase channels, but adds a polarization switching switch. Moreover, the control step of the polarization angle is 120°, which cannot achieve precise polarization matching and results in a large polarization loss. In addition to the three polarization angles that are fully matched, the polarization isolation index of other polarization angles is relatively poor. Summary of the Invention

[0008] To address the shortcomings of the existing technologies, this invention proposes a Ku-band linearly polarized phased array antenna and its control and channel calibration methods to overcome the problems existing in the prior art.

[0009] According to a first aspect of the present invention, a Ku-band arbitrary linear polarization phased array antenna is proposed, comprising a printed circuit board and a signal receiving chip arranged sequentially from top to bottom. The upper surface of the printed circuit board has multiple antenna elements arranged in a rectangular grid. These antenna elements are divided into several antenna subarrays, each consisting of two adjacent 2×2 antenna elements. In each antenna subarray, four antenna elements are centrally symmetrically distributed with the subarray's geometric center as the origin. Each antenna element is a dual-linear polarization element, having a first polarization direction and a second polarization direction perpendicular to the first polarization direction. Within the antenna subarray, the polarization directions of two diagonally positioned antenna elements are rotationally symmetrical about the subarray's geometric center, resulting in opposite phases of the cross-polarization components generated by the two antenna elements. Through the symmetry of the geometric layout, the cross-polarization components generated by the diagonally positioned antenna elements are out of phase (anti-phase). During beamforming, these anti-phase cross-polarization components cancel each other out. This significantly improves the cross-polarization isolation of the antenna array and does not rely on the high isolation performance of individual antenna elements, reducing the difficulty of element design.

[0010] In some specific embodiments, the antenna element is a dual-feed structure, including a first feed point and a second feed point. A local coordinate system is constructed with the geometric center point of the antenna element itself as the origin, and the first feed point and the second feed point are located on the x-axis and y-axis of this local coordinate system, respectively. The signal receiving chip has receiving channels connected to the first feed point and the second feed point, respectively. This configuration eliminates the need for complex external polarization synthesis networks (such as bridges), achieving a high degree of circuit integration and helping to reduce profile height and transmission loss.

[0011] In some specific embodiments, the antenna elements on the upper surface of the printed circuit board are 2N×2N, where N is a positive integer; all antenna elements on the printed circuit board are periodically extended and arranged in a symmetrical layout of antenna subarrays. This configuration ensures that even in large-scale arrays, the overall antenna aperture still possesses excellent cross-polarization isolation characteristics, achieving high-performance modular expansion.

[0012] In some specific embodiments, the phased array antenna is a 2×2 antenna subarray. This configuration provides a modular unit with minimal functionality, suitable for miniaturized terminals or as a basic building block for large-scale arrays, facilitating manufacturing and testing.

[0013] In some specific embodiments, the phased array antenna consists of four antenna subarrays joined together to form a 4×4 array. This setup provides a medium-sized implementation and further validates the effectiveness of symmetrical layouts with multiple subarrays.

[0014] In some specific embodiments, in the phased array antenna, one signal receiving chip is provided for every 2×2 antenna elements; the signal receiving chip is an 8-channel receiving chip, and the 8 RF input ports of the 8-channel receiving chip are respectively connected to a total of 8 feed points of the 2×2 antenna elements. This arrangement allows the horizontal and vertical components of each antenna element to be independently controlled digitally in terms of amplitude and phase, while greatly simplifying the wiring complexity of the analog beamforming network.

[0015] In some specific embodiments, slot lines are provided within the antenna element. This arrangement optimizes the impedance matching characteristics of the antenna element, extends its operating bandwidth, or improves the port isolation of the element itself.

[0016] According to a second aspect of the present invention, an arbitrary linear polarization control method based on the above-described phased array antenna is proposed, comprising the following steps: S1: Obtain the target polarization angle θ of the linearly polarized wave to be synthesized; S2: Based on the quadrant where the target polarization angle θ is located, control the phase difference between the two receiving channels of the first and second feed points connected to the same antenna element. The phase difference is configured to be 0° or 180°. S3: Based on the specific value of the target polarization angle θ in the quadrant, control the amplitude attenuation difference between the two receiving channels of the first and second feed points connected to the same antenna element; S4: By symmetrically arranging the antenna elements within the antenna subarray, the cross-polarization components of the antenna elements are canceled out during signal synthesis. This control method overcomes the accuracy limitations of traditional polarization control relying solely on phase shifters. The polarization direction is determined by phase flipping (0 / 180°), and the polarization angle is finely adjusted using the continuous adjustability of amplitude attenuation. This achieves the synthesis of arbitrary linearly polarized waves across the entire plane (0-180°) with extremely high synthesis accuracy.

[0017] In some specific embodiments, the control strategy for the amplitude attenuation difference is: when 0° θ At 90°, the phase configuration of the channel corresponding to the first feed point is 0°, and the attenuation is configured as Sv; the phase configuration of the channel corresponding to the second feed point is 180°, and the attenuation is configured as Sh; when 90° θ At 180°, the phase configuration of the channel corresponding to the first feed point is 0°, and the attenuation is configured as Sv; the phase configuration of the channel corresponding to the second feed point is 0°, and the attenuation is configured as Sh; where Sv and Sh are the attenuation amounts of the vertical and horizontal channels, respectively. The polarization angle step is controlled by adjusting the difference between Sv and Sh. This transforms the polarization angle control step from being limited by the number of phase shifters (e.g., a step of approximately 2.8° for a 6-phase shifter) to being controlled by the attenuator precision. Since the attenuator adjustment step is usually finer, this method can significantly reduce the polarization angle adjustment step (e.g., to within 1°), achieving extremely high polarization matching accuracy and reducing polarization mismatch losses.

[0018] According to a third aspect of the present invention, a Ku-band linear polarization channel calibration method is proposed, applied to the aforementioned phased array antenna, wherein the signal receiving chip has eight receiving channels RX1 to RX8, and the method includes: When the polarization angle θ = 0° and RX1, RX4, RX5, and RX8 are configured in the maximum attenuation state, a horizontally polarized incident wave is input to the antenna element to correct the RX2, RX3, RX6, and RX7 channels. When the polarization angle θ = 90° and RX2, RX3, RX6, and RX7 are configured in the maximum attenuation state, a vertically polarized incident wave is input into the antenna element to correct the RX1, RX4, RX5, and RX8 channels. When the polarization angle is 0° θ At 90°, an incident wave with 45° polarization is input into the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6 and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to make the signal strength output by each pair of channels the same. When the polarization angle is 90° θ At 135°, an incident wave polarized at 135° is input to the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6, and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to ensure that the signal strength output by each pair of channels is the same. This calibration method effectively eliminates hardware errors introduced by manufacturing errors and inconsistent chip channel gains. It ensures the accuracy of the aforementioned control method, guaranteeing that the polarization angle set by the software matches the actual polarization angle generated by the hardware, thereby maintaining the system's high isolation and high gain.

[0019] Compared with the prior art, the beneficial effects of this application are as follows: 1. Significantly Improved Polarization Isolation: This invention abandons the traditional approach of improving array isolation solely by enhancing the performance of individual antenna elements. Instead, it utilizes a rotationally symmetric 2×2 subarray layout, leveraging geometric characteristics to achieve anti-phase cancellation of cross-polarization components. Even using ordinary dual-polarization antenna elements with average isolation specifications, extremely high cross-polarization isolation (e.g., exceeding 30dB) can be achieved at the array level, meeting stringent satellite communication network access requirements.

[0020] 2. Significantly Improved Polarization Control Accuracy: An innovative control strategy of "phase-defined quadrant, amplitude-defined angle" is proposed. Compared with the problem of traditional double-circular polarization synthesis linear polarization being limited by the number of phase shifters (large control step and low accuracy), this invention utilizes the fine characteristics of the receiver chip channel amplitude adjustment to achieve continuous and fine adjustment of the polarization angle. The polarization control step is smaller (better than 1.6°), which can more accurately match the target polarized wave and reduce polarization loss.

[0021] 3. High system integration and low cost: The antenna unit is directly connected to the multi-channel receiver chip through dual feed points, eliminating the need for complex analog polarization synthesis circuits such as external bridges and couplers. This architecture not only simplifies PCB routing and multi-layer board structure, reducing manufacturing difficulty and cost, but also reduces the insertion loss of the RF link and improves the system's G / T value (gain-noise-temperature ratio).

[0022] 4. The calibration mechanism is comprehensive and highly practical for engineering applications: The supporting channel calibration method can specifically correct the amplitude and phase imbalance between channels, solve the polarization control deviation problem caused by device discreteness in actual engineering, and ensure the high-performance operation of the antenna throughout its entire life cycle.

[0023] 5. Flexible design and easy expansion: Based on the modular design concept of subarray, the antenna architecture can be easily expanded to any 2N×2N scale, and still maintains excellent polarization isolation performance after expansion, making it suitable for satellite communication ground terminals of different sizes. Attached Figure Description

[0024] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the invention. Other embodiments and many anticipated advantages of the embodiments will be readily recognized as they become better understood through reference to the following detailed description. Other features, objects, and advantages of this application will become more apparent from reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a planar layout diagram of a Ku-band arbitrary linear polarization phased array antenna according to an embodiment of this application; Figure 2This is a cross-sectional view of a Ku-band arbitrary linear polarization phased array antenna according to a specific embodiment of this application; Figure 3 This is a connection block diagram of an antenna unit and a signal receiving chip according to a specific embodiment of this application; Figure 4 This is a schematic diagram of the feed point and polarization direction of a square antenna element according to a specific embodiment of this application; Figure 5 This is a schematic diagram of the feed point and polarization direction of a circular antenna element according to a specific embodiment of this application; Figure 6 This is a schematic diagram of the feed point and polarization direction of a slot-coupled fed square antenna element according to a specific embodiment of this application; Figure 7 According to a specific embodiment of this application, 2 Layout diagram of 2 phased array antenna elements; Figure 8 This is according to a specific embodiment of the present application, 4. A schematic diagram of the layout of four phased array antenna elements; Figure 9 This is a schematic diagram of the polarization angle of a Ku-band arbitrary linear polarization phased array antenna according to a specific embodiment of this application; Figure 10 This is a flowchart of an arbitrary linear polarization control method for a phased array antenna according to an embodiment of this application.

[0025] The meaning of each number in the diagram: 1. Antenna unit; 2. Printed circuit board; 3. Signal receiving chip. Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] Figure 1 A planar layout diagram of a Ku-band arbitrary linear polarization phased array antenna according to one embodiment of this application is shown. Figure 1As shown, in this embodiment, the upper surface of the printed circuit board 2 is provided with a plurality of antenna elements 1 arranged periodically in a rectangular grid. Taking the 8×8 array shown in the figure as an example, the multiple antenna elements 1 are spatially divided into several 2×2 antenna subarrays (ANT1 to ANT4 in the figure show a partial schematic of a subarray). In terms of layout structure, every four adjacent antenna elements 1 constitute an independently controlled subarray module, and a signal receiving chip 3 is set at the geometric center position of every four antenna elements 1 (the position shown by the gray square area in the figure). This layout method minimizes the physical distance between each antenna subarray and its corresponding signal receiving chip 3, which helps to simplify the wiring of the printed circuit board 2 and reduce the transmission loss of radio frequency signals.

[0029] Figure 2 A cross-sectional view of a Ku-band arbitrary linearly polarized phased array antenna according to a specific embodiment of this application is shown. Figure 2 As shown, this phased array antenna adopts a multi-layer integrated architecture in the vertical direction, including an antenna element 1, a printed circuit board 2, and a signal receiving chip 3 arranged sequentially from top to bottom. The antenna element 1 is located on the upper surface (top layer) of the printed circuit board 2, serving as a radiator to receive spatial electromagnetic waves; the printed circuit board 2, as a multi-layer dielectric substrate, provides mechanical support and electrical interconnection; the signal receiving chip 3 is flip-chip or surface-mounted on the lower surface (bottom layer) of the printed circuit board 2. The radio frequency port of the signal receiving chip 3 is vertically interconnected with the feed point of the upper antenna element 1 through a metallized via penetrating the printed circuit board 2. This structure effectively achieves a low-profile design and high integration of the antenna array by arranging the active device (chip) and the radiating element (antenna) on the upper and lower sides of the printed circuit board 2, respectively.

[0030] Figure 3 A connection block diagram of an antenna unit and a signal receiving chip according to a specific embodiment of this application is shown. Figure 3As shown, this embodiment illustrates the RF link connection between a 2×2 antenna subarray (containing antenna elements ANT1 to ANT4) and an 8-channel signal receiver chip. Each antenna element is a dual-polarization unit with two isolated feed ports for vertical polarization (V) and horizontal polarization (H). The signal receiver chip integrates eight independent RF signal processing channels (RX1 to RX8), which are connected one-to-one with the eight feed ports of the four antenna elements. In the signal processing flow, the RF signals received at each port enter the chip and undergo low-noise amplification, amplitude weighting (AM), secondary amplification, and phase adjustment (phase shifting) processing in their respective channels. Finally, they are converged to the common output port (COM) through a multi-stage combining network. This architecture ensures that the chip can independently control the amplitude and phase of the horizontal and vertical polarization components of each antenna element, providing a hardware foundation for arbitrary linear polarization combining and polarization isolation optimization.

[0031] Figure 4 A schematic diagram of the feed point and polarization direction of a square antenna element according to a specific embodiment of this application is shown. Figure 4 As shown, in this embodiment, antenna element 1 adopts a square microstrip patch structure. A local rectangular coordinate system is constructed with the geometric center of the antenna element as the origin. Antenna element 1 is a dual-feed structure, with its two feed points (shown as solid black dots in the figure) respectively located on the x-axis and y-axis of this local coordinate system. The feed point on the x-axis corresponds to the horizontal polarization (H) port, and its electric field vector direction points towards (or away from) the center along the x-axis; the feed point on the y-axis corresponds to the vertical polarization (V) port, and its electric field vector direction points towards (or away from) the center along the y-axis. This orthogonally distributed feed structure enables the antenna element to independently receive or transmit two orthogonal linearly polarized waves.

[0032] Figure 5 A schematic diagram of the feed point and polarization direction of a circular antenna element according to a specific embodiment of this application is shown. Figure 5 As shown, in another preferred embodiment, antenna element 1 can also adopt a circular microstrip patch structure. Similar to the aforementioned square element, this circular antenna element also constructs a local coordinate system with its center as the origin, and the first feed point and the second feed point are orthogonally arranged on the x-axis and y-axis, respectively. The H and V arrows in the figure indicate the directions of the main polarization electric field when the horizontal and vertical polarization ports are excited, respectively. It should be noted that, regardless of... Figure 4 The square structure or Figure 5 Due to the presence of dual feed points, the circular structure of the antenna element means that the individual antenna elements are no longer structurally symmetrical about their center line. This inherent asymmetry often introduces cross-polarization components, and the rotationally symmetrical array layout proposed in this application is precisely to solve this problem.

[0033] Figure 6 A schematic diagram of the feed point and polarization direction of a slot-coupled fed square antenna element according to a specific embodiment of this application is shown. Figure 6 As shown, as another optional implementation of this application, antenna element 1 employs a slot-coupled feeding structure. In this structure, electromagnetic coupling excitation of the upper square radiating patch is achieved through slot lines opened on the floor (the central white cross-shaped area in the figure) and microstrip feed lines located below the floor (the dark dashed strip area in the figure). The H and V arrows in the figure indicate the directions of the main polarization electric fields when the horizontal and vertical polarization ports are excited, respectively. It should be noted that although a slot coupling method is adopted, due to the introduction of the dual-line polarization feeding structure (i.e., two sets of orthogonal feed lines and slots), the antenna element still cannot maintain complete symmetry about its central axis in its overall structure. This structural asymmetry also leads to low polarization purity of the antenna element itself, i.e., unsatisfactory polarization isolation performance. Therefore, this embodiment also applies to and relies on the subarray rotational symmetry layout method proposed in this application to improve the overall polarization isolation performance of the array.

[0034] Figure 7 2 shows a specific embodiment according to this application. A schematic diagram of the layout of two phased array antenna elements. Figure 7 As shown, this embodiment details the 2×2 antenna subarray layout that constitutes the core module of the phased array antenna of this application. The subarray consists of four antenna elements (labeled ANT1 to ANT4), with a Cartesian coordinate system constructed around the geometric center of the subarray as the origin. The core innovation of this application lies in the rotationally symmetric layout of the antenna elements: the polarization orientations of two diagonally positioned antenna elements (e.g., ANT1 and ANT3, or ANT2 and ANT4) are centrally rotationally symmetric about the origin. Specifically, as shown by the arrows in the figure, the horizontal polarization (H) of ANT1 points to the left and the vertical polarization (V) points upwards, while the horizontal polarization of its diagonal counterpart, ANT3, points to the right and the vertical polarization points downwards; the two are physically rotated 180 degrees apart. This structural design ensures that during polarization synthesis, the cross-polarization components generated by the structural asymmetry of individual antenna elements are exactly opposite in phase, thus canceling each other out and significantly improving cross-polarization isolation at the subarray level.

[0035] Figure 8 4 shows a specific embodiment according to this application. A schematic diagram of the layout of four phased array antenna elements. Figure 8 As shown, this embodiment demonstrates the use of... Figure 7The array arrangement is formed by periodically expanding the 2×2 subarrays. The entire 4×4 array is composed of four of the aforementioned 2×2 antenna subarrays, containing a total of 16 antenna elements. On a larger array scale, all antenna elements still follow the rule of symmetrical distribution along the global X and Y axes (i.e., the antenna elements in the ±OX and ±OY regions are arranged symmetrically). This layout strategy ensures that whether operating as an independent 2×2 module or expanded into a larger 2N×2N array, the antenna system can always maintain the reverse cancellation state of each cross-polarization component. Through this array-level structural optimization, this application can achieve excellent cross-polarization isolation performance across the entire array aperture without imposing stringent requirements on the isolation performance of individual antenna elements.

[0036] Figure 9 A schematic diagram of the polarization angle of a Ku-band arbitrary linearly polarized phased array antenna according to a specific embodiment of this application is shown. Figure 9 As shown in the figure, this diagram defines the polarization angular coordinate system for synthesizing linearly polarized waves according to this application. The planar rectangular coordinate system formed by the dashed lines in the figure corresponds to the two-dimensional plane where the antenna array is located, where the X-axis corresponds to the horizontal polarization direction and the Y-axis corresponds to the vertical polarization direction. The solid arrow represents the polarization vector direction of the synthesized linearly polarized wave, and the angle between this polarization vector and the positive half-axis of the X-axis is defined as the polarization angle θ. The control method of this application achieves polarization matching for arbitrary linearly polarized waves by jointly adjusting the amplitude and phase of the horizontal and vertical polarization channels, enabling the polarization vector of the synthesized wave to rotate continuously and accurately within the range of 0° to 180° in this coordinate system.

[0037] Figure 10 A flowchart illustrating an arbitrary linear polarization control method for a phased array antenna according to an embodiment of this application is shown. Figure 10 As shown, the polarization control method proposed in this application mainly includes four key steps: S1: Obtain the target polarization angle θ of the linearly polarized wave to be synthesized; S2: Based on the quadrant where the target polarization angle θ is located, control the phase difference between the two receiving channels of the first and second feed points connected to the same antenna element. The phase difference is configured to be 0° or 180°. S3: Based on the specific value of the target polarization angle θ in the quadrant, control the amplitude attenuation difference between the two receiving channels of the first and second feed points connected to the same antenna element; S4: By symmetrically arranging the antenna elements within the antenna subarray, the cross-polarization components of the antenna elements are canceled out during signal synthesis.

[0038] Specifically, when θ=0°, the control status of each channel of signal receiving chip 3 is shown in Table 1: Table 1 ; Here, Smax indicates that the channel is controlled to the maximum attenuation state. For a 6-bit attenuator, the maximum attenuation is typically 31.5dB. Smin indicates that after channel amplitude correction, the attenuator in the channel will no longer add additional attenuation.

[0039] Specifically, when θ = 90°, the control status of each channel of signal receiving chip 3 is shown in Table 2: Table 2 ; Specifically, when 0° θ At 90°, the specific control status of each channel of signal receiving chip 3 is shown in Table 3: Table 3 ; Where Sh and Sv represent the attenuation of the horizontal and vertical channels after deducting channel amplitude correction, respectively.

[0040] Tables 4 and 5 show the polarization angles of the linearly polarized waves formed when Sh-Sv are positive and negative, as well as the step size of the polarization angle change. Compared to the phase modulation method using dual circular polarization units, this method reduces the step size of the polarization angle change from 2.8° to 1.6°, enabling more precise polarization angle control.

[0041] Table 4 ; Table 5 ; Table 6 shows 90° θ The amplitude and phase control of the 180° channel. Sh and Sv represent the attenuation of the horizontal and vertical channels after deducting the channel amplitude correction, respectively.

[0042] Table 6 ; Tables 1 to 6 together reveal and verify the technical effectiveness of the core control strategy of "phase-defined quadrant and amplitude-defined angle" in this application: by determining the quadrant interval where the polarization vector is located through a specific phase configuration (0° / 180°) (as shown in Tables 1-3 and 6), and by using the nonlinear mapping relationship of the amplitude attenuation difference between channels (as shown in Tables 4-5), the polarization angle is finely adjusted, and the control accuracy of the linear polarization angle is significantly improved from about 2.8° limited by traditional phase shifters to within 1.6° (optimally reaching 0.1°), thereby realizing high-precision continuous synthesis and matching of arbitrary linear polarization waves.

[0043] According to another aspect of the present invention, a Ku-band linear polarization channel calibration method is also proposed, applied to the aforementioned phased array antenna, wherein the signal receiving chip has eight receiving channels RX1 to RX8, and the calibration method includes: When the polarization angle θ = 0° and RX1, RX4, RX5, and RX8 are configured in the maximum attenuation state, a horizontally polarized incident wave is input to the antenna element to correct the RX2, RX3, RX6, and RX7 channels. When the polarization angle θ = 90° and RX2, RX3, RX6, and RX7 are configured in the maximum attenuation state, a vertically polarized incident wave is input into the antenna element to correct the RX1, RX4, RX5, and RX8 channels. When the polarization angle is 0° θ At 90°, an incident wave with 45° polarization is input into the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6 and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to make the signal strength output by each pair of channels the same. When the polarization angle is 90° θ At 135°, an incident wave polarized at 135° is input to the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6, and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to ensure that the signal strength output by each pair of channels is the same. This calibration method effectively eliminates hardware errors introduced by manufacturing errors and inconsistent chip channel gains. It ensures the accuracy of the aforementioned control method, guaranteeing that the polarization angle set by the software matches the actual polarization angle generated by the hardware, thereby maintaining the system's high isolation and high gain.

[0044] This application presents the above description merely as a preferred embodiment and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A Ku-band arbitrary linear polarization phased array antenna, characterized in that, The device includes a printed circuit board and a signal receiving chip arranged sequentially from top to bottom. The upper surface of the printed circuit board has multiple antenna elements arranged in a rectangular grid. These antenna elements are divided into several antenna subarrays, each consisting of two adjacent 2×2 antenna elements. Within each subarray, four antenna elements are centrally symmetrically distributed with the subarray's geometric center as the origin. Each antenna element is a dual-polarization unit, having a first polarization direction and a second polarization direction perpendicular to the first polarization direction. Within each subarray, the polarization directions of two diagonally positioned antenna elements are rotationally symmetrical about the subarray's geometric center, resulting in opposite phases for the cross-polarization components generated by the two antenna elements.

2. The phased array antenna according to claim 1, characterized in that, The antenna unit is a dual-feed structure, including a first feed point and a second feed point; a local coordinate system is constructed with the geometric center point of the antenna unit itself as the origin, and the first feed point and the second feed point are located on the x-axis and y-axis of the local coordinate system, respectively; the signal receiving chip has receiving channels connected to the first feed point and the second feed point, respectively.

3. The phased array antenna according to claim 1, characterized in that, The antenna elements on the upper surface of the printed circuit board have a size of 2N×2N, where N is a positive integer; all antenna elements on the printed circuit board are periodically extended and arranged in a symmetrical layout according to the antenna subarray.

4. The phased array antenna according to claim 3, characterized in that, The phased array antenna is a 2×2 antenna subarray.

5. The phased array antenna according to claim 3, characterized in that, The phased array antenna is formed by splicing together four antenna subarrays to form a 4×4 array.

6. The phased array antenna according to claim 2, characterized in that, In the phased array antenna, one signal receiving chip is provided for every 2×2 antenna elements; the signal receiving chip is an 8-channel receiving chip, and the 8 RF input ports of the 8-channel receiving chip are respectively connected to a total of 8 feed points of the 2×2 antenna elements.

7. The phased array antenna according to claim 2, characterized in that, The antenna element has a slotted wire inside.

8. A method for arbitrary linear polarization control of a phased array antenna based on any one of claims 1-7, characterized in that, Includes the following steps: S1: Obtain the target polarization angle θ of the linearly polarized wave to be synthesized; S2: Based on the quadrant where the target polarization angle θ is located, control the phase difference between the two receiving channels of the first feed point and the second feed point connected to the same antenna element, wherein the phase difference is configured to be 0° or 180°. S3: Based on the specific value of the target polarization angle θ in the quadrant, control the amplitude attenuation difference between the two receiving channels of the first feed point and the second feed point connected to the same antenna element; S4: By symmetrically arranging the antenna elements within the antenna subarray, the cross-polarization components of the antenna elements are canceled out during signal synthesis.

9. The arbitrary linear polarization control method for a phased array antenna according to claim 8, characterized in that, The control strategy for the amplitude attenuation difference is as follows: when 0° θ At 90°, the phase configuration of the channel corresponding to the first feed point is 0°, and the attenuation is configured as Sv; the phase configuration of the channel corresponding to the second feed point is 180°, and the attenuation is configured as Sh; when 90° θ At 180°, the phase configuration of the channel corresponding to the first feed point is 0°, and the attenuation is configured as Sv; the phase configuration of the channel corresponding to the second feed point is 0°, and the attenuation is configured as Sh; where Sv and Sh are the attenuation amounts of the vertical channel and the horizontal channel, respectively, and the polarization angle step is controlled by adjusting the difference between Sv and Sh.

10. A Ku-band linear polarization channel calibration method, applied to the phased array antenna according to any one of claims 1-7, characterized in that, The signal receiving chip has eight receiving channels RX1 to RX8, and the method includes: When the polarization angle θ = 0° and RX1, RX4, RX5, and RX8 are configured in the maximum attenuation state, a horizontally polarized incident wave is input to the antenna element to correct the RX2, RX3, RX6, and RX7 channels. When the polarization angle θ = 90° and RX2, RX3, RX6, and RX7 are configured in the maximum attenuation state, a vertically polarized incident wave is input into the antenna element to correct the RX1, RX4, RX5, and RX8 channels. When the polarization angle is 0° θ At 90°, an incident wave with 45° polarization is input into the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6 and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to make the signal strength output by each pair of channels the same. When the polarization angle is 90° θ At 135°, an incident wave polarized at 135° is input into the antenna element. The RX1 / RX2, RX3 / RX4, RX5 / RX6 and RX7 / RX8 channels are compared pairwise, and the channel attenuation is adjusted to make the signal strength output by each pair of channels the same.

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